In a semiconductor manufacturing process, it is necessary to cut a die close to the edge of a wafer in order to obtain as many dies as possible from one wafer. Accordingly, with respect to a charged particle beam device and an optical inspection device used in a semiconductor manufacturing process, there is a demand for detecting the height of the wafer close to the edge of the wafer with high accuracy, in order to measure or examine close to the edge of the wafer with high accuracy. Further, there is a demand for high speed height-detection in order to realize high throughput for the semiconductor manufacturing process. In the present invention, the foregoing can be achieved by the following configuration: sandwiching a target region on a wafer, a first pattern and a second pattern are projected onto one side and the other side respectively of the target region from an oblique direction with respect to the wafer top-surface, enabling an image of the first pattern and/or second pattern to be used.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A charged particle beam device comprising: a stage; a projection optical system that projects a first pattern on one side and a second pattern on another side across at least a part of a scanning area of a charged particle beam on a wafer placed on the stage, the first pattern and the second pattern being projected from an oblique direction with respect to a surface of the wafer; and an imaging device that obtains images of the first pattern and the second pattern, wherein at least one of the images of the first pattern and the second pattern is chosen to measure a height of the wafer, wherein the projection optical system further comprises a plurality of first slits that projects the first pattern via a first slit group, and a plurality of second slits that projects the second pattern via a second slit group, and the plurality of first slits are disposed at a first side with respect to an optical axis of the projection optical system, and the plurality of the second slits are disposed at a second side with respect to the optical axis of the projection optical system.
2. The charged particle beam device according to claim 1 , wherein when the image of the first pattern lacks in the vicinity of the edge of x axis or y axis of the stage, the second pattern is chosen to measure the height of the wafer.
3. The charged particle beam device according to claim 1 , wherein the plurality of the first slits and the plurality of the second slits are arranged in a short side direction of the first and second slit groups, respectively.
4. A charged particle beam device comprising: a stage movable in at least a height direction; a projection optical system that projects a first pattern on one side and a second pattern on another side across at least a part of a scanning area of a charged particle beam on a wafer placed on the stage, the first pattern and the second pattern being projected from an oblique direction with respect to a surface of the wafer; and a detection optical system that detects a light emitted from the projection optical system and reflected by the surface of the wafer, wherein, on the wafer, the second pattern is projected to an area on the wafer closer to the projection optical system compared with the first pattern, and the first pattern is projected on one side and the second pattern is projected on another side across a projection of an optical axis of the projection optical system on the surface of the wafer, wherein the projection optical system further comprises a plurality of first slits that projects the first pattern via a first slit group, and a plurality of second slits that projects the second pattern via a second slit group, and the plurality of first slits are disposed at a first side with respect to the optical axis of the projection optical system, and the plurality of the second slits are disposed at a second side with respect to the optical axis of the projection optical system.
5. The charged particle beam device according to claim 4 , wherein the first pattern and the second pattern each have a pitch smaller than a distance between the first pattern and the second pattern.
6. The charged particle beam device according to claim 4 , wherein the stage has a height adjusted based on at least one of the first pattern and the second pattern.
7. The charged particle beam device according to claim 6 , wherein the height of the stage is adjusted based on at least one of the first pattern and the second pattern in accordance with a lack of an image of the first pattern or the second pattern.
8. An optical inspection device comprising: a stage movable in at least a height direction; a projection optical system that projects a first pattern on one side and a second pattern on another side across a field of view on a wafer placed on the stage, the first pattern and the second pattern being projected from an oblique direction with respect to a surface of the wafer; and an imaging device that obtains images of the first pattern and the second pattern, wherein at least one of the images of the first pattern and the second pattern is chosen to adjust a height the stage, wherein the projection optical system further comprises a plurality of first slits that projects the first pattern via a first slit group, and a plurality of second slits that projects the second pattern via a second slit group, and the plurality of first slits are disposed at a first side with respect to an optical axis of the projection optical system, and the plurality of the second slits are disposed at a second side with respect to the optical axis of the projection optical system.
9. The optical inspection device according to claim 8 , wherein at least one of the images of the first pattern and the second pattern is chosen to adjust the height of the stage in accordance with a position of the field of view.
10. The optical inspection device according to claim 8 , wherein at least one of the images of the first pattern and the second pattern is chosen to adjust the height of the stage in accordance with a lack of the image of the first pattern or the second pattern.
11. The optical inspection device according to claim 8 , wherein, on the wafer, the first pattern is projected to an area on the wafer closer to the projection optical system compared with the second pattern.
12. The optical inspection device according to claim 8 , wherein the height of the stage is adjusted based on a change in positions of a plurality of strength peaks included in the chosen image.
13. The optical inspection device according to claim 9 , wherein the first pattern is projected on one side and the second pattern is projected on another side across a projection of an optical axis of the projection optical system on the surface of the wafer.
14. The optical inspection device according to claim 12 , further comprising: a first detection optical system that detects a scattered light in a first direction; and a second detection optical system that detects the scattered light in a second direction.
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January 12, 2017
November 10, 2020
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